1. Field of the Invention
The present invention relates to a tire pressure monitoring device and more particularly to a tire pressure monitoring device capable of receiving tire pressure signals with different protocols.
2. Description of the Related Art
A conventional tire pressure monitoring device has a tire pressure sensor mounted on each tire of a vehicle. After detecting a tire pressure of the tire, each tire sensor transmits a detection result to a tire condition receiver of the vehicle with a wireless signal. The tire condition receiver receives the wireless signal to determine whether each of the tires is in a normal condition. If any one of the tire sensors detects an abnormal condition, the tire condition receiver generates an audio alarm or a visual alarm to inform a driver of the vehicle that the tire pressure is abnormal.
However, each tire pressure sensor and the tire condition receiver of the conventional tire pressure monitoring device have to use the same protocol to execute a signal encoding, a signal transmission, and a signal decoding. If any of the tire pressure sensors or the tire condition receiver breaks down, a repairman has to replace the broken tire pressure sensor or the broken tire condition receiver with a new one of the same type or the same protocol. Hence, manufacturers or suppliers have to prepare different types of tire pressure sensors or tire condition receivers using different protocols, and hence production and inventory costs are both high. If the broken tire pressure sensor or the broken tire condition receiver is out of stock or out of production, the repairman has to replace the whole tire pressure monitoring device with a new one.
Therefore, a conventional tire pressure monitor mounted on a tire of a vehicle has a sensor, a storage device and a transmitter. The transmitter is electrically connected respectively with the sensor and the storage device. The sensor detects a tire pressure of the tire. The storage device stores codes that include at least one data format. The transmitter of the tire pressure monitor transforms a tire pressure information of the sensor and the code stored in the storage device into a wireless signal and transmits the wireless signal to an external device.
Said disclosed tire pressure monitor analyzes and obtains a protocol of the conventional tire pressure sensor, and then the protocol is written to a new tire pressure sensor through a professional appliance or a computer equipment, that is, an original protocol of the new tire pressure sensor is replaced by the protocol of the conventional tire pressure sensor to correspond to the conventional external device such as an electronic control unit of the vehicle.
When writing a protocol to a new tire pressure sensor, the repairman has to conduct the setting process several times depending on the number of the tires the vehicle has. For a normal four-wheel vehicle, the repairman has to conduct the setting process four times. Hence, a sequence of mounting a new tire pressure sensor consumes a lot of time.
When writing a protocol to a new tire pressure sensor, IDs of each tire pressure sensor are usually set and stored at the same time. The repairman has to respectively assign different IDs to each new tire pressure sensor. If the writing of the protocol and the IDs takes place prior to the mounting of the new tire pressure sensor, the new tire pressure sensor has to be mounted on a tire at a specific location according to a specific ID; otherwise the tire pressure information cannot be recognized. If the mounting of the new tire pressure sensor takes place prior to the writing of the protocol and the IDs, the repairman has to move around the vehicle in the proximities of each tire for setting the protocols such that the work process is complex and time-consuming, and the writing of the protocol and the IDs could be interfered with and shielded by a metal wheel disk of the tire, thereby causing operating problems such as a write failure.
In conclusion, the conventional tire pressure monitor requires replacing the protocol of the new tire pressure sensor with the protocol of an old tire pressure sensor and has problems such as the complex and time-consuming process and the write failure caused by the metal wheel disk.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.